Bowel Care and Cardiovascular Function After Spinal Cord Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bowel Care and Cardiovascular Function After Spinal Cord Injury (NCT01567605), a randomized phase 4 study. The primary outcome is Blood Pressure Change During Bowel Care.

2. Clinical Question

Bowel care can be accompanied by changes in blood pressure and heart rate after spinal cord injury. The investigators proposed that a lubricant containing lidocaine might lessen these cardiovascular changes. The clinical question was therefore whether the reported blood pressure measure differed between bowel-care occasions using lidocaine and occasions using placebo.

The comparison was conducted within a crossover design: participants were assigned to a sequence, used one lubricant first, and then used the other after a washout period. This design makes the contrast relevant to repeated bowel-care occasions in the same participant, rather than only to a comparison between separate groups. It also means the analysis needs to account for the relationship between observations from the same person. The registry record does not report whether the analysis did so.

The record identifies blood pressure change during bowel care as the primary outcome, measured continuously during the routine. Heart rate was described in the study rationale, while the posted primary outcome is blood pressure. The record does not report a separate primary heart-rate outcome or a clinical threshold for interpreting the blood pressure difference. The question addressed by the posted results is consequently a statistical comparison of the recorded blood pressure measure, not a judgment about an individual participant’s cardiovascular response.

3. Trial Design

This was a randomized, phase 4 crossover trial sponsored by Simon Fraser University. The registry record lists the study as completed, with an enrollment of 13. The listed start was 2012-03 and primary completion was 2018-12. The condition was spinal cord injury.

Participants followed one of two treatment sequences. In one sequence, lidocaine lubricant was used first and placebo lubricant after a washout period; in the other, placebo was used first and lidocaine after the washout. The washout period is described, but its duration is not reported in the registry record. The study summary says that each participant was assessed on two occasions within 28 days. The exact scheduling and any departures from the planned sequence are not reported.

The registry metadata labels masking as quadruple. The study summary separately describes the trial as double-blind and specifically says that the subject and the Nurse Continence Advisor assisting with testing would not know which lubricant was used for each test. The record does not explain how these masking descriptions relate to one another.

The primary measure was recorded continuously during bowel care, for up to one hour on each occasion, using a finger blood pressure cuff identified as a Finometer. Bowel care could occur at home or at an investigator facility. The summary says that participants would have privacy during the routine. Secondary measures included the duration of bowel care, cardiovascular symptoms assessed by questionnaire after care, and heart beat abnormalities recorded during care.

The registry record gives outcome summaries by lubricant condition. Because the design is crossover, those condition summaries should not automatically be read as independent-group observations. The record does not report a crossover-specific statistical model, adjustment for treatment period or sequence, or a method for accounting for within-participant correlation.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: All participants met eligibility criteria and were randomised to treatment in a crossover manner.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Blood Pressure Change During Bowel Care, measured over Measured continuously during bowel care (approximately one hour) on two occasions within 28 days..

The primary endpoint is titled “Blood Pressure Change During Bowel Care.” The record describes beat-to-beat blood pressure measurement using a finger cuff during the bowel-care routine, with measurement continuing for up to one hour on each occasion. The stated timeframe is continuous measurement during bowel care on two occasions within 28 days. The outcome is reported as a mean in mmHg with a standard error.

Continuous monitoring is relevant to the study question because the investigators were interested in cardiovascular changes occurring during the routine, rather than only a reading taken at a single time. A continuous record can capture variation across the bowel-care episode. The registry record does not specify how the continuous readings were reduced to the reported endpoint, such as which time points or summary rule were used. It also does not define a clinically meaningful difference or state whether the reported mean represents a change from a baseline measurement, a summary of readings during care, or another derived measure. The endpoint title uses “change,” while the detailed description focuses on continuous blood pressure recording.

The posted mean was 90.5 mmHg for lidocaine lubricant and 80.0 mmHg for placebo lubricant. The unadjusted mean difference was 10.5 mmHg, with a confidence interval from -20.81 to 41.81 and an unadjusted p-value of 0.511. These summaries describe the recorded comparison; they do not establish how the values relate to a clinical threshold or to a particular participant’s usual blood pressure. The record does not report the analysis method used by the investigators to derive the primary outcome contrast.

7. Results Posted in the Registry

• Lidocaine Lubricant: mean 90.50 versus 80.00 on control; difference 10.50 (95% CI -20.81 to 41.81), standardized effect d = 0.26; z-test p = 0.511.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Duration of Bowel Care Routine

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Lidocaine Lubricant: mean 79.10 versus 57.70 on control; difference 21.40 (95% CI -1.76 to 44.56), standardized effect d = 0.71; z-test p = 0.070.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine Lubricant and the control. The interval gives the range of effects that remain compatible with the data.

Cardiovascular Symptoms During Bowel Care

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Lidocaine Lubricant: mean 7.60 versus 7.00 on control; difference 0.60 (95% CI -4.30 to 5.50), standardized effect d = 0.09; z-test p = 0.810.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine Lubricant and the control. The interval gives the range of effects that remain compatible with the data.

Heart Beat Abnormalities During Bowel Care (Number of Participants With Heart Beat Abnormalities)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Lidocaine Lubricant: 27.3% (3/11) versus 18.2% (2/11) on control; risk difference 9.1 percentage points (95% CI -25.7 to 43.9), risk ratio 1.50 (0.31–7.30); unadjusted two-proportion z-test p = 0.611.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Lidocaine Lubricant and the control. The interval gives the range of effects that remain compatible with the data.

Across the secondary outcomes, the posted estimates do not point uniformly in a single direction or convey the same degree of precision. They cover a continuous measure of routine duration, a questionnaire score for cardiovascular symptoms, and a binary count of participants with heart beat abnormalities. These outcomes address different aspects of bowel care, so a pattern in one should not be treated as a direct substitute for the primary blood pressure measure.

The secondary findings do not provide a clear confirmation of the primary comparison. They are additional descriptions that may help characterize the study, but the registry record does not report investigator analyses for them or a prespecified hierarchy linking them to the primary outcome. Their unadjusted comparisons should consequently carry less weight than a fully specified primary analysis. In particular, testing several outcomes without a reported multiplicity strategy increases the possibility that an apparently notable result could arise by chance across the set.

The outcome types also have different statistical properties. Mean differences for continuous outcomes summarize average values, whereas a count of participants with an abnormality is a binary measure whose precision depends on the number of participants and observed events. The record reports fewer participants for the binary endpoint than for the continuous outcome summaries. Sparse event information naturally limits how much can be learned about that outcome from the posted comparison.

None of these secondary results resolves the limitations of the primary estimate, including uncertainty about how the crossover design was analyzed. They may be useful for generating questions for a larger or more fully reported study, but they do not establish a general cardiovascular effect. The registry record does not report a secondary-outcome analysis plan, adjustment for multiple comparisons, or clinical thresholds for interpreting the symptom score or routine duration.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Duration of Bowel Care Routine
• Cardiovascular Symptoms During Bowel Care
• Heart Beat Abnormalities During Bowel Care (Number of Participants With Heart Beat Abnormalities)

9. Statistical Interpretation

10. Statistical Methods Explained

For continuous outcomes, the registry record reports a mean for each lubricant condition, a standard error for each mean, and a contrast expressed as a mean difference. The mean describes the average recorded outcome in that condition. A standard error describes the precision of the estimated mean: smaller standard errors generally indicate a more precisely estimated mean, while larger ones indicate greater uncertainty. A standard error is not the same as the standard deviation, which describes variability among observations. The record does not report standard deviations for the primary arm summaries.

What does the mean difference describe?

The mean difference compares the reported mean under lidocaine with the reported mean under placebo. For the primary endpoint, the posted means are 90.5 mmHg and 80.0 mmHg, and the recalculated unadjusted contrast is 10.5 mmHg. A positive contrast in this presentation means that the reported lidocaine mean is higher than the placebo mean. The value alone does not tell whether that difference is clinically important. The registry record does not report a threshold for clinical importance or a formal interpretation rule for the endpoint.

These are summary-statistic calculations, not a reported investigator model. A recalculated, unadjusted contrast is useful for describing what follows from the posted summaries, but it may not match the analysis appropriate to the design. The registry record reports no investigator analyses for the primary or secondary outcomes. It also does not provide a statistical analysis plan from which to determine what model or adjustment was intended.

Why does the crossover structure matter?

In a crossover study, participants receive both conditions in a specified order. Measurements from the same participant are typically related: a person’s outcome under one condition may be associated with that person’s outcome under the other. A paired analysis uses that within-participant relationship. An analysis that treats the two condition summaries as if they came from unrelated groups can omit information about the pairing and may represent uncertainty differently. The posted arm summaries do not give the participant-level paired differences or their variability, so a paired contrast cannot be reconstructed from the record.

Period and sequence can also matter. An outcome may vary between the first and later occasions, independent of the lubricant. A crossover analysis may need to account for the period in which each treatment was used and the sequence to which participants were assigned. Carryover is a further general concern when an effect from an earlier treatment could persist into a later period. The record says that there was a washout period but does not give its duration or report analyses of period, sequence, or carryover effects. It is not possible to determine from the posted summaries whether these issues affected the estimates.

How should a p-value be read?

In general, a p-value describes how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. The primary unadjusted p-value is 0.511. Its interpretation depends on an analysis model, but the registry record does not state an investigator model or report a model-based analysis. The p-value should therefore be treated as part of the unadjusted comparison rather than as a complete account of the trial evidence.

For continuous outcomes, the general assumptions behind methods based on normal approximations include an appropriate representation of the outcome distribution and the sampling variation. For a crossover analysis, assumptions about the paired data and the treatment-period structure also matter. The record does not report diagnostic checks or the method used to assess these assumptions. It also does not report whether the primary outcome was adjusted for any baseline or design variables.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability is greater than a statistical model expects. It can make standard errors too small if the model does not account for the extra variation, leading to overly narrow intervals or p-values that appear more decisive than warranted. This concept is most relevant to outcomes modeled as counts or binary events, although the appropriate concern depends on the model. The record does not report a model for heart beat abnormalities or any assessment of over-dispersion. Its binary summaries are sparse, so the uncertainty around those comparisons is important to keep in view.

All recalculated comparisons are unadjusted summaries from the posted results. No adjustment for multiple outcomes is reported. No investigator-reported statistical analyses are listed, and the registry record does not describe the statistical plan, handling of missing observations, or analysis population. These missing details prevent a complete assessment of whether the reported summaries reflect the intended methods for this randomized crossover trial.

11. Confidence Intervals and Precision

The primary mean difference is 10.5 mmHg, with a posted confidence interval from -20.81 to 41.81. A confidence interval is a way to express uncertainty around an estimate: a narrower interval indicates greater precision, while a wider interval indicates less precision. The interval covers values on either side of zero, including differences in the direction of a lower lidocaine mean as well as differences in the direction of a higher lidocaine mean. The registry record does not report the confidence level used for this interval.

The interval is wide relative to the point estimate, so the unadjusted estimate does not pin down the magnitude or direction of the difference closely. This should not be interpreted as evidence that all values within the interval are equally plausible, nor does the interval give the probability that the true effect lies inside it. Its interpretation depends on the statistical method and assumptions used to construct it. The record does not identify the investigator’s interval method; the displayed comparison is an unadjusted recalculation from posted summary statistics.

The reported standard errors for the two condition means are 13.4 and 8.7. They give context for uncertainty in those means, but do not describe the distribution of individual blood pressure readings. In a crossover trial, the precision of a treatment contrast can depend on the correlation between each participant’s observations under the two conditions. That paired information is not reported, so these summaries cannot establish how much precision a crossover-specific analysis might gain or lose.

The unadjusted p-value of 0.511 is consistent with the uncertainty expressed by the interval, but neither statistic proves equivalence or absence of an effect. The registry record does not report an equivalence margin, a non-inferiority margin, or a clinically important difference. Without such a criterion, the interval can describe statistical precision but cannot by itself determine whether the range of possible contrasts would matter clinically.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size estimates are planning illustrations based on the observed effect, not the trial’s own original design assumptions. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The planned effect to detect is varied across the listed fractions of the observed effect. For these outcomes, the figures are participants per arm; a time-to-event outcome would instead use total events, but no time-to-event outcome is listed in these results.

The 80% power column describes the number of participants per arm estimated to be needed for an 80% chance of detecting the selected effect under those assumptions, if that effect is real and the analysis conditions are met. The 90% power column uses a higher chance of detection and therefore generally requires a larger planned sample for the same assumed effect. These are design calculations, not results about how likely the completed trial was to detect its effect. This is not observed power.

Rows that plan for a smaller fraction of the observed effect require more participants because a smaller difference is harder to distinguish from random variation. The estimates are sensitive to the observed effect used as their starting point. When that effect is uncertain, as it is in a trial with an imprecise posted contrast, planning directly from it can produce unstable estimates. These calculations do not establish that the original trial was designed using the stated assumptions: the original sample-size justification and assumptions are not reported in the registry record.

The trial’s crossover structure also matters when using these illustrations for design. The stated planning assumptions describe equal allocation between two arms and a normal approximation, but the record does not report a crossover-specific planning method, paired-data correlation, or any adjustment for the treatment sequence. The registry record also does not report whether the sample-size estimates incorporate potential missing outcomes or multiplicity. The estimates are therefore best read as simplified planning scenarios, not as a definitive recommendation for a future study.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 10.500; pooled standard deviation σ = 40.732.
2. n = 2 × (1.96 + 0.842)² × 40.732² / 10.500² = 236.2, rounded up to 237 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 10.5                      # observed difference in means
sigma <- 40.732358144355                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1567605)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 237 (80% power), 317 (90% power)
 75% of observed effect: n per arm = 420 (80% power), 563 (90% power)
 50% of observed effect: n per arm = 945 (80% power), 1,265 (90% power)
power.t.test: 237.2 
Simulated power at n = 237 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes or statistical comparisons are assessed. As the number of opportunities to find a result increases, the chance of at least one apparently unusual result can also increase, even when no underlying difference exists. Common approaches include prioritizing a primary outcome, specifying a testing hierarchy, or adjusting inference across a family of tests. In general, the choice should be planned in advance and reported so readers can distinguish confirmatory from exploratory findings.

The registry record identifies a primary outcome and lists three secondary outcomes. It does not report a multiplicity adjustment, a testing hierarchy, or a plan for interpreting the secondary outcomes alongside the primary outcome. The posted secondary comparisons are unadjusted. They should therefore be treated as exploratory descriptions rather than independent confirmatory evidence. The record does not report whether other planned outcomes or analyses were omitted from the posted results.

The record does not report how missing data were handled, whether any measurements were unavailable, or how incomplete crossover periods were treated. It also does not define the analysis population, such as whether analyses were based on all randomized participants or only participants with measurements under both conditions. Without this information, the role of missing observations and exclusions in the outcome summaries cannot be evaluated.

For this crossover design, analysis populations and missingness can be especially relevant because a participant may have data for one treatment period but not the other. A complete-pair analysis, a model that uses available observations, and other approaches can make different assumptions. The registry record does not say which approach was used. It also does not report how period, sequence, or within-participant correlation was handled.

The record lists no investigator-reported analyses for the outcomes. The statistical analysis plan, original sample-size justification, missing-data strategy, analysis populations, and multiplicity approach are not reported in the registry record. These omissions limit assessment of whether the posted findings reflect prespecified analyses and how robust they might be to alternative reasonable methods.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event figures are reported by treatment sequence: lidocaine lubricant followed by placebo, and placebo followed by lidocaine. The registry record lists 7 participants at risk in the first sequence and 6 in the second. Serious adverse events affected 0 participants in each sequence, and deaths were 0 in each sequence. Other adverse events affected 0 participants in each sequence as well.

These figures describe what was recorded in the registry for the listed groups. They do not establish that no adverse events could occur, and they do not measure the risk precisely. The record does not provide event descriptions, event timing by treatment period, severity beyond the serious-event category, or details about how events were collected. The figures are presented by sequence rather than as a detailed treatment-period comparison, so they do not show whether an event was associated with one lubricant or the other.

With this small enrolled study and no recorded events in these categories, the safety summaries have limited ability to characterize uncommon harms. They should be read as an account of the events reported in the registry record, not as evidence that either lubricant is free of risk.

16. What the Result Does, and Does Not, Mean

The posted primary result is an unadjusted comparison of blood pressure summaries during bowel care with lidocaine lubricant and placebo lubricant. The estimated mean difference is 10.5 mmHg, with an interval from -20.81 to 41.81 and an unadjusted p-value of 0.511. The point estimate is in the direction of a higher reported mean under lidocaine, but its uncertainty includes values in both directions. The result does not provide a precise estimate of the size or direction of a difference.

This finding does not establish that lidocaine lubricant changes blood pressure, nor does it establish that the two lubricants have equivalent effects. The registry record does not report an equivalence or non-inferiority framework, a clinically important difference, or a clinical threshold for the outcome. A lack of a small p-value is not proof of no effect; it may also reflect uncertainty in the estimate.

The result also cannot be generalized without qualification beyond the participants and setting described in this record. The study focused on bowel care after spinal cord injury, with measurements during routine care and outcomes recorded on two occasions within 28 days. The enrollment was 13. The record does not provide enough information to assess how representative these participants were of a broader population, or whether the results would be similar in other settings or with other bowel-care routines.

The crossover design could support a within-person comparison, but the registry record does not report whether the posted estimate accounts for paired observations, period, or sequence. It reports no investigator analyses. Consequently, the comparison is most appropriately read as a descriptive unadjusted result from the posted summaries, not as a complete analysis of the trial design.

The secondary outcomes and adverse-event summaries add context but do not overcome these limitations. Their unadjusted nature, the absence of a reported multiplicity plan, and the sparse event information mean that they cannot settle the primary question. Overall, the registry record documents the comparison and its uncertainty, but it does not provide a fully reported inferential analysis or a basis for clinical recommendations.

17. Why This Trial Matters Statistically

This trial is statistically interesting because it applies a randomized crossover design to a repeated, real-world care routine. In principle, having participants use both lubricants can make each person a reference for their own outcome. That feature may reduce the influence of stable differences between people. To realize that benefit, however, the analysis must represent the pairing and account for the timing and order of treatments. The registry record does not report whether it did so.

The posted primary comparison illustrates why an estimate should be read together with its precision. The mean difference is 10.5 mmHg, but the interval extends from -20.81 to 41.81. The point estimate alone might draw attention to a difference in one direction, while the interval makes clear that the unadjusted data are compatible with a broad range of contrasts. Reporting both helps prevent an estimate from being mistaken for a precise conclusion.

The study also illustrates a distinction between statistical non-significance and evidence of equivalence. The unadjusted p-value is 0.511, but the record does not define an equivalence margin or present a design intended to establish equivalence. A result that is not statistically significant cannot, by itself, establish that any difference is absent or unimportant.

Finally, the record shows why reporting the analysis plan matters. The crossover structure, unreported missing-data handling, absence of investigator analyses, and lack of a multiplicity strategy make it difficult to assess how the summary comparisons should be interpreted. Clear reporting of paired methods, participant flow, uncertainty, and prespecified outcome handling would make the statistical evidence more transparent.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The principal limitation is that the registry record does not provide an investigator-reported analysis for the primary endpoint. The comparison available for interpretation is an unadjusted recalculation from posted summaries. Because this is a crossover study, participant-level paired data and the method used to account for repeated measurements are particularly important, but are not reported.

The outcome description leaves some ambiguity about what the primary summary represents. The title refers to blood pressure change, while the detailed description says blood pressure was recorded continuously during bowel care. The record does not explain how beat-to-beat recordings were summarized, whether a baseline was used, or what time window contributed to each reported mean. It also does not report a threshold for a clinically meaningful difference.

Details that would help assess the design are missing from the registry record: the duration of the washout, the handling of treatment period and sequence, and any assessment of carryover. The record does not describe missing-data handling, analysis populations, participant exclusions, or whether all participants completed both treatment periods. These are material uncertainties for interpreting a crossover comparison.

The registry labels masking as quadruple, while the study summary describes double-blinding and names the participant and assisting Nurse Continence Advisor as unaware of treatment. The record does not reconcile those descriptions. It also does not report the original sample-size justification or the statistical plan.

Other limitations include the modest enrollment, the absence of reported investigator analyses, and the lack of a stated multiplicity approach for secondary outcomes. The binary heart beat abnormality outcome has fewer participants represented than the continuous outcomes, and its event summaries are sparse. The adverse-event record provides no event descriptions or timing by treatment period. These omissions limit both statistical and safety interpretation.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Bowel Care and Cardiovascular Function After Spinal Cord Injury — NCT01567605.
• Registry record last updated 2023-02-08; status last verified 2022-05.
• Results first posted 2023-02-08.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

The registry record describes a completed, randomized, phase 4 crossover trial sponsored by Simon Fraser University, with enrollment of 13 and a listed start of 2012-03. Primary completion was 2018-12. Participants used lidocaine lubricant and placebo lubricant in randomized sequence, with a washout period between conditions.

The primary outcome was blood pressure change during bowel care, recorded continuously and reported as a mean with standard error. The unadjusted mean difference was 10.5 mmHg, with a confidence interval from -20.81 to 41.81 and p = 0.511. Secondary outcomes covered routine duration, cardiovascular symptoms, and heart beat abnormalities.

The record does not report investigator analyses, a crossover-specific analysis method, a multiplicity plan, or missing-data handling. The posted comparisons therefore describe the available outcome summaries but do not provide a fully specified analysis of the trial design.